1. Field of the Invention
The present invention starts from a pressure exchanger for internal-combustion engines, with a central axis and with an at least single-series cellular wheel which is arranged on this central axle and is equipped with cells and the cells of which interact in a specific time sequence on the one hand with channels in a hot-gas guide housing and on the other hand with channels in an air guide housing.
2. Discussion of Background
A pressure exchanger is known from Patent Specification CH-550,937. The cellular wheel interacts with an air guide housing and with a hot-gas guide housing. In the cells the sucked-in air is compressed in a known way and is then diverted by means of high-pressure air channels of the air guide housing into a combustion chamber of an internal-combustion engine. As is known, the hot gases which were used for the pressure exchange flow off from the cells of the cellular wheel and further through channels in the hot-gas guide housing into a gas turbine. At the same time, fresh air is sucked in and fills the corresponding cells of the cellular wheel up again. This operation of pressure exchange can take place in a known way either by a reversal process or by a throughflow process.
At comparatively high speeds of the cellular wheel, it can happen that the flow-off of the hot gases from the cells of the cellular wheel is impeded because of insufficient flushing energy, the result of which is that too little fresh air also flows after them into the cells. In the separating zone between the fresh air and hot gases, the two components are intermixed in the cells, with the result that too little clean fresh air subsequently enters the internal-combustion engine, thereby reducing its efficiency. Both the cellular wheel and the housings have to be manufactured with comparatively high precision, since only then can a sufficiently small play between the cellular wheel and the housings be obtained. A reduction of the play in order thereby to increase the efficiency of the pressure exchanger necessitates check measurements involving a high outlay and mechanical reworking of the components, thus making production more expensive.